The exec task should support the input redirection. In other words, I'd like to redirect stdin of the new process to a file that I specify through the exec task.
ant 1.6 has these 2 attributes in the exec task. input : A file from which the executed command's standard input is taken. This attribute is mutually exclusive with the inputstring attribute. inputstring : A string which serves as the input stream for the executed command. This attribute is mutually exclusive with the input attribute. See this link : http://ant.apache.org/manual-1.6beta/CoreTasks/exec.html